Disperse dye compositions have heretofore been prepared by adding dispersants, e.g., sulfonic acid salts of phenol-formaldehyde low condensates, to dye material in as large amounts as 0.5 to 2 times the dye material, and finely dispersing the dye material usually in water. These disperse dye compositions have very high dispersibility. It is preferred, however, to reduce the dispersant content of the disperse dye composition because the dispersant is discarded to waste water after dyeing.
Japanese Patent Application (OPI) No. 6689/78 (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") discloses a water-diffusible high concentration dye composition for continuous dyeing or printing, containing a disperse dye and 30 to 150% by weight, based on the weight of the disperse dye, of a compound represented by the general formula: EQU R.sub.1 (OC.sub.2 H.sub.4).sub.l (OC.sub.3 H.sub.6).sub.m X
wherein R.sub.1 is a saturated or unsaturated alkyl group containing 1 to 20 carbon atoms, an acyl group containing 4 to 30 carbon atoms, or an aryl, alkaryl or aralkyl group containing 6 to 30 carbon atoms, l is an integer of 1 or more, m is 0 or an integer of 1 or more, l+m is from 35 to 200, l/m is at least 2, X is a hydroxyl group, OSO.sub.3 M, SO.sub.3 M, OPO.sub.3 HM or OPO.sub.3 M.sub.2, and M is an alkali metal ion or a quaternary ammonium ion.
The above dye composition increases the viscosity due to a large amount of the dispersant used to the dye and a large molecular weight of the dispersant, and causes disadvantages such as generation of heat, foaming or the like in the production steps. Further, the dye composition is not satisfactory in the dispersion and coloration properties.